Changes in Material Classification of the Urinary Bladder Wall After Spinal Cord Injury

Author(s):  
D. Claire Gloeckner ◽  
Michael B. Chancellor ◽  
Michael S. Sacks

Changes in the mechanical properties of the urinary bladder wall following neurogenic disease or trauma can result in bladder dysfunction. We have recently reported changes in the biaxial mechanical properties of the bladder wall 10 days after spinal cord injury in a rat model [1]. Development of a constitutive model to characterize these changes would facilitate quantitative comparisons and provide the necessary information for organ-level computational modeling. However, before an appropriate constitutive model of the bladder wall can be formulated, its material class must be identified. In the present study, we applied a generalized method for material classification of biaxial mechanical data to our previous data on the urinary bladder wall.

Author(s):  
Silvia Wognum ◽  
Michael S. Sacks

Spinal cord injury (SCI) is accompanied by urologic complications, characterized by two phases (early areflexic phase and late hyperreflexic phase), where the routine function of the urinary bladder of storing urine and voiding becomes compromised. In addition to functional deficiencies, these pathologies are often accompanied by changes in bladder wall tissue morphology and mechanical properties. Our experimental studies have revealed that the bladder wall can undergo rapid remodeling post-SCI (figs.1,2) and exhibits complex biomechanical responses (fig.2B) [1,2,3,4]. These remodeling events will result in profound changes in bladder wall biomechanical behavior (fig.2) and ultimately organ function. The specific alterations in mechanical behavior and functional properties of bladder wall tissue and the underlying mechanisms are not well understood. A multi-phase structural constitutive model of the bladder wall is clearly needed to understand how changes in various tissue components produce observed changes in bladder function.


2008 ◽  
Vol 36 (9) ◽  
pp. 1470-1480 ◽  
Author(s):  
Kevin K. Toosi ◽  
Jiro Nagatomi ◽  
Michael B. Chancellor ◽  
Michael S. Sacks

2002 ◽  
pp. 2247-2252 ◽  
Author(s):  
D. CLAIRE GLOECKNER ◽  
MICHAEL S. SACKS ◽  
MATTHEW O. FRASER ◽  
GEORGE T. SOMOGYI ◽  
WILLIAM C. de GROAT ◽  
...  

2002 ◽  
Vol 167 (5) ◽  
pp. 2247-2252 ◽  
Author(s):  
D. CLAIRE GLOECKNER ◽  
MICHAEL S. SACKS ◽  
MATTHEW O. FRASER ◽  
GEORGE T. SOMOGYI ◽  
WILLIAM C. de GROAT ◽  
...  

2012 ◽  
Vol 46 (2) ◽  
pp. 237-245 ◽  
Author(s):  
Joanna H.L. Diong ◽  
Robert D. Herbert ◽  
Lisa A. Harvey ◽  
Li Khim Kwah ◽  
Jillian L. Clarke ◽  
...  

2006 ◽  
Vol 6 ◽  
pp. 2445-2449 ◽  
Author(s):  
Subramanian Vaidyanathan ◽  
Peter L. Hughes ◽  
Bakul M. Soni

In a male patient with cervical spinal cord injury, the urinary bladder may go into spasm when a urethral catheter is removed and a new Foley catheter is inserted. Before the balloon is inflated, the spastic bladder may push the Foley catheter out or the catheter may slip out of a small-capacity bladder. An inexperienced health professional may inflate the balloon of a Foley catheter in the urethra without realizing that the balloon segment of the catheter is lying in the urethra instead of the urinary bladder. When a Foley balloon is inflated in the urethra, a tetraplegic patient is likely to develop autonomic dysreflexia. This is a medical emergency and requires urgent treatment. Before the incorrectly placed Foley catheter is removed, it is important to document whether the balloon has been inflated in the urinary bladder or not. The clinician should first use the always available tools of observation and palpation at the bedside without delays of transportation. A misplaced balloon will often be evident by a long catheter sign, indicating excessive catheter remaining outside the patient. Radiological diagnosis is not frequently required and, when needed, should employ the technique most readily available, which might be a body and pelvic CT without intravenous contrast. An alternative radiological technique to demonstrate the position of the balloon of the Foley catheter is described. Three milliliters of nonionic X-ray contrast medium, Ioversol (OPTIRAY 300), is injected through the side channel of the Foley catheter, which is used for inflating the balloon. Then, with a catheter-tip syringe, 30 ml of sterile Ioversol is injected through the main lumen of the Foley catheter. Immediately thereafter, an X-ray of the pelvis (including perineum) is taken. By this technique, both the urinary bladder and balloon of the Foley catheter are visualized by the X-ray contrast medium. When a Foley catheter has been inserted correctly, the balloon of the Foley catheter should be located within the urinary bladder, but when the Foley catheter is misplaced with the balloon inflated in the urethra, a round opaque shadow of the Foley balloon is seen separately below the urinary bladder. This radiological study takes only a few minutes to perform, can be carried out bedside with a mobile X-ray machine, and does not require special expertise or preparations, unlike transrectal ultrasonography. When a Foley balloon is inflated in the urethra, abdominal ultrasonography will show an absence of the Foley balloon within the bladder. The technique described above aids in positive demonstration of a Foley balloon lying outside the urinary bladder. Such documentation proves valuable in planning future treatment, education of health professionals, and settlement of malpractice claims.


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